It all starts with a note folded into the shape of an origami octopus: If you believe this and the other origami notes that follow—which middle schooler Meade Macon absolutely, positively does —the concept of parallel dimensions is true, and there is a convention full of alternate versions of Meade waiting for his RSVP. It's got to be a joke. Except . . . the octopus is an origami fold Meade thought he invented. And the note writer has a lot of intel on him that nobody else should know. I mean, he's told his best friend Twig a lot about himself, but he's definitely kept mum about that time he sleepwalk-peed into his Lego container when he was six. Could Me Con be a real thing? And should he go?